let obj = {
    
    'jia': function(a,b){
       console.log(a+b);
        
    },
    'jian': function(a,b){
        console.log(a-b);

        
    },
    'cheng': function(a,b){
        console.log(a*b);

    },
    'chu': function(a,b){
        console.log(a/b);

    },
    'new': function(a,b){
        this.jia(a,b);
        this.jian(a,b);
        this.cheng(a,b);
        this.chu(a,b);
    }
};
module.exports=obj;